Inserting in Word document

[George]

I've created a diagram that I'm inserting into a MS Word
document. When I first inserted it, I could double click
on it, and then Visio would start up and I could edit the
diagram in the Word document. I can't get Visio to crank
back up again, now, however, and I need to make another
change. How can I do this without making the change in
the original document and reinserting? It would be a lot
easier to make the change to the inserted portion.

--George